Refractory composition board and the process for producing the same.



UNITED STATES PATENT OFFICE.

ROY ALFRED PLUMB AND CLARENCE R. WEED, OF DETROIT, MICHIGAN, ASSIGNORS TO. TRUSSED CONCRETE STEEL COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICIIIGAN.

REFRACTORY COMPOSITION BOARD AND THE PROCESS FOR PRODUCING THE SAME.

To all whom it may concern:

Be it known that we, ROY ALFRED PLUMB and CLARENCE R. W ED, both citizens of the United States, and residents of Detroit, in the county of Wayne and State of Michigan, have invented a new and useful Befractory Composition Board and the Process for Producing the Same, of whichthe following is a specification.

This-invention relates to water and fireresistant sheets or boards for building purposes, and its object. is to produce a sheet or board which shall have surfaces of great toughness thoroughly united to the body, and which shall be substantially fire and water proof.

This invention consists in the process of forming a building board or sheet and of the board or sheet itself, embodying a body portion, which, while being constructed, consists of water and hydraulic cement, either neat or extended by incorporating sand or other inert fillers, and a layer or mat of refractory interlacing fibers united with atleast one of the surfaces of the body by means of a portion of the'hydraulic cement which composes the body being carried out by the excess water which is mechanically forced from said body through said layer of fibers, the cement being deposited in thespaces between said fibers.

This building material may be formedas follows; The main body of the board is,

essentially a hydraulic cement mixed in a proper container with enough water to form a paste.- If desired, sand or other inert filler may be added. 7 A layer or mat of asbestos fibers, preferably wet, is spread on a wire screen, felt belt or other foraminous carrier, and a layer of wet plastic body material is then spread onlthe fibers. If desired, a second screen or belt carrying a layer or matof fibers may be placed on the plastic body material in such a manner as to bring the mat indirect contact with the plastic mass. The excess water is then removed from the plastici body by pressure. or suction or both by means of any proper,

mechanism. the water passes --out throughthe mats, it carries fine particles of cement with it, filling the minute spaces between the interlacing fibers, and thus form-- ing a perfeetbond between the fibrous sur- Specification of Letters Patent.

Patented Nov. 9, 1915 Application filed May 26, 1915. Serial No. 30,553.

face layer and the body of the board, no line of demarcation occurring.

The supporting screens or belts are stripped from the board as soon as it is stiff enough to be handled, and the board may then be densified by the application of high pressure. By this process, the layers of interlacing fibers are caused to act as filters to retain the fineparticles of cement, thereby becoming coated and the.

voids or spaces between them becoming filled. As these particles have undergone a rapid colloidal development, the cement will be especially elastic. The resultant board then has one or two surface layers of elastic hydraulic cement reinforced by means of interlacing refractory fibers, and therefore constitutes a building material having great transverse strength and which is substantially fire and water proof. 7

If high pressure is applied to the com pleted board while it is still in a semi-plastic state, a smooth and slate-like surface will be obtained and any voids remaining in the surface will be filled by matter extruded,

from the body. This pressure is also advantageous in further amalgamating the surface layers and the body, since the extruded portions of the cement that project into the mats of fibers serve to unite the mats to the body and effectually prevent their separation. Freshly formed boards have relahard as the cement sets. This hardening may be accelerated by heating up to about the boiling point of water. These boards -may'be made in continuous sheets on proper machines, and other fireproof materials such as mineral'wool may be substituted for the asbestos fibers. The surfaces of the board may be densified and polished by means of smooth rolls and superior results obtained.

spall when heated to hightemperatures.

. Nor does disintegration occur because of surface cracks which often fillwith water, which, when frozen, enlarges the cracks. The surfaces produced by the present process are veryf tough and both fire and s5 tively little strength but become strong and T weather resistant, and are formed innultaneously and bonded integrally with the main body of the structure. Because of the particles of cement being deposited by the water flowing outwardly through the layers or mats, the change in structure and composition is gradual from the body to the outer surface of the layer of fibers.

The addition of water-proofing material to the surface coat is desirable, but not essential, for a board formed in the described manner with a surface heavily reinforced with asbestos fibers and integrally bonded to the body will have superior resistant properties. It is also possible by our process to color these boards as may be desired by introducing the coloring agent in the surface mixture only, that is, by mixing with the fibers, thereby effecting a saving in manufacturing cost without in any way making the product inferior. It is also possible to apply the fibers and other substances in a dry form to the surface of the plastic body by means of an air blast, a rotating cylinder or other device and then incorporating them with the body as heretofore described.

We are aware that mixtures of hydraulic cement and asbestos are well known, but our process differs from any hitherto known in that the surface of the sheet or board is protected by a layer of asbestos fiber freshly formed and united thereto before the cement has set."

We claim 1. A composition board consisting of a body of hydraulic cement-and a layer of asbestos fibers united to one surface of the body by the cement extending through and filling the spaces between the fibers and thereby locking the fibers to the body.

2. The process of forming a composition board with a colored surface which consists in placing fibers mixed with colorin matter upon the surface of a plastic bo y containing hydraulic cement and water and mechanically expelling the water from the body through the fibrous surface and thereby filling the spaces between the fibers with the fine particles of cement carried by the water and causing a gradual change in structure and composition from the body to the surface which is colored and reinforced by interlacing fibers.

3. The process of manufacturing a composition board which consists in placing upon a plastic body containing hydraulic cement and water a loose surface coating containing fibers and a water-proofing agent and subsequently by mechanical means-filling the voids between these fibers with maoeterial extruded from the body. so that the waterproofing agent remains in the surface of the board and there is a gradual change in structure from the body of the boardto a surface which is water-proofed and reinforced with interlacing fibers.

4. The process of manufacturing a composition board which consists in placing fibers upon the surface of a plastic body containing hydraulic cement and water and causing these fibers to become coated with fine colloidal particles of cement carried from the plastic body by the water which is being expelled from the body so that the surface fibers become cemented to each other and to the body of the board by a tough and colloidal cement.

5. The process of manufacturing a com.- position board which consists in placing a loose pulp of fibrous material mixed with water upon one or both surfaces of a plastic body containing hydraulic cement mixed to a paste with water, and mechanically withdrawing the water from the whole mass through the surface fibers and collecting in the voids between the fibers the fine particles of cement forced to the surface of the board, thus filling the voids cementing the fibers and causing a gradual change in composition and structure from the surface to the body of the board.

6. The process of manufacturing a reinforced composition board which consists in placing upon a plastic body containing hydraulic cement and water a loose surface containing fibers and thereafter by mechanical pressure or suction filling the voids between these fibers with material extruded from the body so that the surface becomes in efl'ect, a portion of the body reinforced by interlacing fibers.

7. The process of manufacturing a com.- position. board which consists in placing upon a plastic body comprising hydraulic cement and water a layer of fibers and thereafter causing a portion of the water in the plastic body to flow out through the layer of fibers and thereby carry a portion of the hydraulic cement into the spaces between the fibers.

8. The process of manufacturing a composition board which consists in placing upon a plastic body comprising hydraulic cement and water a layer of fibers and thereafter creating a lesser relative pressure on the outer surface of the layer than at the interior of the' body, thereby causing a portion of the water in the body tofiow out through the layer of fibers and thereby carry a portion of the hydraulic cement into the spaces between the fibers. v

9. The process of manufacturing a rein forced, fire-proof composition board from hydrauliccement, fibrous material and water which consists in forming the body of the board as a plastic mass between two layers of surface coating containing fibrous material, mechanically withdrawing through the surface fibers the water so that the fine cementfparticles which are withdrawn from the body with the water fill the voids between the fibers, and compacting the surface coatings and the body as the water is. mechanically expelled so as to weld the whole into a board with no sharp line of division between the surface and the body but with a gradual change in structure and composition from the main part of the body to a dense and compact surface strengthened and reinforcedby interlacing fibers.

10. The process of manufacturing a reinforced, fire-proof composition board from hydraulic cement, fibrous material and water which consists in forming the body of the board as a plastic mass between two layers of surface coating containing fibrous material, mechanically withdrawing through the surface fibers the water which carries the fine cement particles into the fibers, completely filling the voids between the fibers, and comas to weld pacting the surface coatings so the whole into a board with no sharp line of division between the surface and the body, but a gradual change in structure and composition from the main part of the body to a dense and compact surface, strengthened and reinforced by interlacing fibers.

11. The process of manufacturing a reinforced composition board which consists in placing the fibers in loose form' upon the surface of a plastic body containing essentially hydraulic cement and water, mechanically expressing the water from the Whole mass through the surface fibers, and collecting the fine particles of cement, carried to the surface of the board, thus filling the voids, cementing the fibers and causing a gradual change in composition and structure from the surface to the body of the board..' o

In testimony whereof we have signed this specification.

ROY ALFRED PLUMB. CLARENCE R. WE D. 

